The thing with games like DMC and the new Ninja Gaiden is you needed to find the boss pattern to win. It basically forces you to play one way, and if not, you just die.

Not only die, but take just three hits die!

To me, this is where games lose the value of being fun. To coin a phrase I read somewhere... "One doesn't need a microscope (or a strategy guide) to figure out a boss". It should be done within the game itself.

One of the most enjoyable boss fights was against the White Knight in DMC4. Primarily because:

1. Damage per hit wasn't too bad, so you don't die in three hits.
2. You can actually beat the boss in different ways
3. You can keep plugging away and occasionaly dodge AS NEEDED

Basically the boss fight felt like a fighting game. On SF you never knew what the computer would do, they just react what you do and you do the same. It's not like "At the start of the round, Ryu will do a jumping roundhouse kick, a crouching forward kick and a fireball... I better hold forward and start the shoryuken motion".

Sadly on most boss fights its like that, even on DMC4. You knew the plant lady was going to do this move first, therefore you should block, then this move, so you should dodge, and then this move - that's when you strike back. Then she gets stunned so you do the devil trigger and lay waste on her.

Ninja Gaiden even stepped in up a notch when the only way you could beat bosses was to do the jumping strike move which stunned most of them and start the launch in the air combo.